Authors of a research letter in this week’s issue of THE LANCET conclude that vitamin B12 in addition to folic acid should be used to fortify food to lower concentrations of the blood protein homocysteine, thereby potentially reducing the risk of cardiovascular disease.
Mandatory fortification of grain foods with folic acid has been in place in the USA since 1998, and evidence suggests that this measure has resulted in a 19% reduction in occurrence of neural-tube defects in babies. In the UK, mandatory folic-acid fortification is now a possibility after recommendations by the Government’s Committee on Medical Aspects of Food and Nutrition Policy (COMA). Fortification of food with folic acid to prevent neural-tube defects also lowers plasma homocysteine, which is a risk factor for cardiovascular disease. Joe McPartlin from Trinity College, Dublin, Ireland, and colleagues in Ulster University at Coleraine, Northern Ireland, investigated the effect of both folic acid and vitamin B12 supplementation on homocysteine concentrations.
30 men and 23 women received sequential supplementation with increasing doses of folic acid. After supplementation, the usual dependency of homocysteine on folic acid diminished, and vitamin B12 became the main determinant of plasma-homocysteine concentration.
Joe McPartlin comments: “This finding suggests that a fortification policy based on folic acid and vitamin B12, rather than folic acid alone, is likely to be much more effective in lowering homocysteine concentrations, with potential benefits for reduction of the risk of cardiovascular disease.”
Contact: Dr Joe McPartlin, Vitamin Research Unit, Department of Clinical Medicine, Sir Patrick Duns Laboratory, CPL, St James's Hospital, Dublin 8, Ireland; T) +353 1 608 2105; F) +353 1 608 3551; E) jmcprtln@tcd.ie
The Lancet